Ruth Chepngetich of Kenya obliterated the women's world record by almost two minutes on Sunday as she won the Chicago Marathon in 2 hours, 9 minutes and 56 seconds.

The 30-year-old Chepngetich, who became the first three-time women's winner of the Chicago race, broke the previous world record of 2hours, 11minutes 53 seconds set by Ethiopia's Tigst Assefa last year in Berlin.

"I feel so great, I'm proud of myself. This is my dream that has come true," said Chepngetich, the 2019 world marathon champion. "I've fought a lot, thinking about the world record and I have fulfilled it."

In the absence of Olympic champion Sifan Hassan, the 2023 Chicago winner, Chepngetich set a blazing early pace and reached the halfway point in 1:04:16, the fifth-quickest time in history for a half marathon by a woman.

"The weather was perfect and I was well prepared. The world record was in my mind," said Chepngetich, runner-up to Hassan 12 months ago.

At one point, Chepngetich was on track to shave more than three minutes off the world record.

She slowed slightly in the closing kilometres but still had plenty in the tank and beat her own personal best by four-plus minutes, which she had clocked when winning the race two years ago.

Ethiopia's Sutume Kebede came second on Sunday, while Chepngetich's Kenyan compatriot, Irine Cheptai, finished third. (AFP)